The Mushkin Enhanced Joule 1000W power supply efficiency isn't quite up there with other power supplies in this class, with a dip to 77% on 110Vac at 957W loading; it's very close but it makes no claims to the contrary. The user manual claims efficiencies of 85% and 87% for mains input voltages of 115Vac and 230Vac respectively when subjected to a typical load. What is a typical load? It's open to interpretation, but I feel it's reasonable to assume this power supply would "typically" be installed in a fairly high specification gaming rig with a single very high-end or dual graphics card configuration requiring somewhere in the region of 400W~600W. Power supply peak efficiency is almost universally reached somewhere in the region of 50% of its maximum rated DC output power, a level at which the Mushkin Enhanced Joule 1000W power supply exhibited efficiencies of 84% (115Vac) and 86% (230Vac) which are very close to the levels given in the user manual. Once again, like the Mushkin Enhanced Volta 600W, it does what it says on the tin.

Power factor levels and efficiency easily meet the requirements of the ATX12V V2.2 specification and it just goes to prove that you can still find efficient power supplies that don't carry 80 Plus certification. I appreciate it wouldn't pass muster with the 80 Plus organisation based on these figures, but how many PC enthusiasts would run this unit at, or near full power? The Mushkin Enhanced Joule 1000W exhibits great mid-range efficiency but it will lose points for the below-par efficiency at full load on 110Vac.

AC Ripple On DC Outputs:

I have consistently found the AC ripple levels on the DC rails to be more or less equal with a 110VAC or 230VAC mains supply. The results given below are for 230VAC only but I will continue to check the levels at 110VAC during testing and publish them below if there are any significant differences.

AC ripple/noise on the +3V3 rail at 230VAC

Oscilloscope settings: Amplitude = 5mv/div, Timebase = 5uS/div

AC ripple/noise on the +5V0 rail at 230VAC

Oscilloscope settings: Amplitude = 5mv/div, Timebase = 5uS/div

AC ripple/noise on the +12V rail at 230VAC

Oscilloscope settings: Amplitude = 5mv/div, Timebase = 5uS/div

AC ripple/noise on the -12V rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 5uS/div

AC ripple/noise on the +5VSB rail at 230VAC

Oscilloscope settings: Amplitude = 5mv/div, Timebase = 5uS/div

Mushkin Enhanced Joule 1000W

AC Ripple/Noise

DC Rail

+3V3

+5V0

+12V

-12V0

+5VSB

ATX12 Max (mV p-p)

50

50

120

120

50

Ripple (mV p-p)

30

40

30

65

45

Pass/Fail

Pass

Pass

Pass

Pass

Pass

The Mushkin Enhanced Joule 1000W power supply produced a reasonable set of results in this section, with all the AC ripple/noise levels meeting the requirements of the ATX12V V2.2 specification.